A spokesman for Rep. Alan Grayson, who angered Republicans last year when he said they wanted sick Americans to "die quickly," told FoxNews.com that Florida Democrat is helping a constituent who was affected by the sign to file a complaint next week with the proper authorities. Grayson will also file additional complaints with all relevant boards or agencies,  Grayson spokesman Todd Jurkowski said.

The notice on Dr. Jack Cassell's Mount Dora practice says, "If you voted for Obama, seek urologic care elsewhere. Changes to your healthcare begin right now, not in four years."

Cassell told Fox News on Friday he wasn't refusing care to patients but wanted to educate them on how the new health care law would affect them.

"I came across the timeline for implementation of Obamacare and I got a little discouraged when I got to next year when I found that most of the ancillary services and nursing homes and diagnostic imaging, all these things start to fade away," he told Fox News' Neil Cavuto. "And I felt that my patients really need to know about this. And the more I thought about it, the angrier I got until I finally felt like I'm going to put a little splash page on my front door and just get people thinking a little bit."

A spokeswoman from the Florida Department of Health, which licenses physicians and investigates complaints, said Friday there was no law prohibiting Cassell from advertising himself this way.

"Because there is no statute, there would be no grounds for a complaint," spokeswoman Eulinda Smith said. "It would be legally deficient."

But Grayson appears undeterred, arguing the Cassell has violated the Hippocratic Oath when he turned away patients on the basis of political beliefs.

His spokesman, Jurkowski, told FoxNews.com that at least one person followed the instructions on the sign and there could have been more.

"I think a reasonable person would deemed that being turned away," Jurkowski said.

A University of Florida professor said Cassell is walking a thin line between free speech and professional obligation. William Allen, a specialist in bioethics, law and medical professionalism, said civil rights protections can prevent patient discrimination. But the law only provides for race, gender, religion, sexual orientation and disability -- not political opinion.

Allen said Cassell may be within his rights if he doesn't quiz patients about their politics and hasn't refused to see anyone.

"(He's) trying to hold onto the nub of his ethical obligation," Allen said. "But this is pushing the limit."

Cassell has been practicing in the area since 1988. His wife, Leslie Campione, is a lawyer and GOP candidate for the county commission.

Cassell told Fox News that most patients have been extremely supportive.

"Ninety eight percent are energized," he said. "And once they read this timeline, they can't believe it. I started out just trying to figure out how to educate my patients but think every doctor in the United States needs to put this in their office."

The Associated Press contributed to this report.